From mboxrd@z Thu Jan  1 00:00:00 1970
From: jason@lakedaemon.net (Jason Cooper)
Date: Wed, 10 Apr 2013 15:16:41 -0400
Subject: [PATCH v7 1/5] drivers: memory: Introduce Marvell EBU Device
 Bus driver
In-Reply-To: <1365620644-15790-2-git-send-email-ezequiel.garcia@free-electrons.com>
References: <1365620644-15790-1-git-send-email-ezequiel.garcia@free-electrons.com>
 <1365620644-15790-2-git-send-email-ezequiel.garcia@free-electrons.com>
Message-ID: <20130410191641.GG28693@titan.lakedaemon.net>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

gregkh,

On Wed, Apr 10, 2013 at 04:04:00PM -0300, Ezequiel Garcia wrote:
> Marvell EBU SoCs such as Armada 370/XP, Orion5x (88f5xxx) and
> Discovery (mv78xx0) supports a Device Bus controller to access several
> kinds of memories and I/O devices (NOR, NAND, SRAM, FPGA).
> 
> This commit adds a driver to handle this controller. So far only
> Armada 370, Armada XP and Discovery SoCs are supported.
> 
> The driver must be registered through a device tree node;
> as explained in the binding document.
> 
> For each child node in the device tree, this driver will:
>   * set timing parameters
>   * register a child device
>   * setup an address decoding window, using the mbus driver
> 
> Keep in mind the address decoding window setup is only a temporary hack.
> This code will be removed from this devbus driver as soon as a proper device
> tree binding for the mbus driver is added.
> 
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  .../bindings/memory-controllers/mvebu-devbus.txt   | 156 ++++++++++
>  drivers/memory/Kconfig                             |  10 +
>  drivers/memory/Makefile                            |   1 +
>  drivers/memory/mvebu-devbus.c                      | 340 +++++++++++++++++++++
>  4 files changed, 507 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt
>  create mode 100644 drivers/memory/mvebu-devbus.c

As every commit to drivers/memory has been signed by you, would you like
to take this patch through your tree?  Or, I'll take it through arm-soc
with your Ack to keep the series together.

thx,

Jason.

> 
> diff --git a/Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt b/Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt
> new file mode 100644
> index 0000000..653c90c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/memory-controllers/mvebu-devbus.txt
> @@ -0,0 +1,156 @@
> +Device tree bindings for MVEBU Device Bus controllers
> +
> +The Device Bus controller available in some Marvell's SoC allows to control
> +different types of standard memory and I/O devices such as NOR, NAND, and FPGA.
> +The actual devices are instantiated from the child nodes of a Device Bus node.
> +
> +Required properties:
> +
> + - compatible:          Currently only Armada 370/XP SoC are supported,
> +                        with this compatible string:
> +
> +                        marvell,mvebu-devbus
> +
> + - reg:                 A resource specifier for the register space.
> +                        This is the base address of a chip select within
> +			the controller's register space.
> +                        (see the example below)
> +
> + - #address-cells:      Must be set to 1
> + - #size-cells:         Must be set to 1
> + - ranges:              Must be set up to reflect the memory layout with four
> +                        integer values for each chip-select line in use:
> +                        0 <physical address of mapping> <size>
> +
> +Mandatory timing properties for child nodes:
> +
> +Read parameters:
> +
> + - devbus,turn-off-ps:  Defines the time during which the controller does not
> +                        drive the AD bus after the completion of a device read.
> +                        This prevents contentions on the Device Bus after a read
> +                        cycle from a slow device.
> +
> + - devbus,bus-width:    Defines the bus width (e.g. <16>)
> +
> + - devbus,badr-skew-ps: Defines the time delay from from A[2:0] toggle,
> +                        to read data sample. This parameter is useful for
> +                        synchronous pipelined devices, where the address
> +                        precedes the read data by one or two cycles.
> +
> + - devbus,acc-first-ps: Defines the time delay from the negation of
> +                        ALE[0] to the cycle that the first read data is sampled
> +                        by the controller.
> +
> + - devbus,acc-next-ps:  Defines the time delay between the cycle that
> +                        samples data N and the cycle that samples data N+1
> +                        (in burst accesses).
> +
> + - devbus,rd-setup-ps:  Defines the time delay between DEV_CSn assertion to
> +			DEV_OEn assertion. If set to 0 (default),
> +                        DEV_OEn and DEV_CSn are asserted at the same cycle.
> +                        This parameter has no affect on <acc-first-ps> parameter
> +                        (no affect on first data sample). Set <rd-setup-ps>
> +                        to a value smaller than <acc-first-ps>.
> +
> + - devbus,rd-hold-ps:   Defines the time between the last data sample to the
> +			de-assertion of DEV_CSn. If set to 0 (default),
> +			DEV_OEn and DEV_CSn are de-asserted at the same cycle
> +			(the cycle of the last data sample).
> +                        This parameter has no affect on DEV_OEn de-assertion.
> +                        DEV_OEn is always de-asserted the next cycle after
> +                        last data sampled. Also this parameter has no
> +                        affect on <turn-off-ps> parameter.
> +                        Set <rd-hold-ps> to a value smaller than <turn-off-ps>.
> +
> +Write parameters:
> +
> + - devbus,ale-wr-ps:    Defines the time delay from the ALE[0] negation cycle
> +			to the DEV_WEn assertion.
> +
> + - devbus,wr-low-ps:    Defines the time during which DEV_WEn is active.
> +                        A[2:0] and Data are kept valid as long as DEV_WEn
> +                        is active. This parameter defines the setup time of
> +                        address and data to DEV_WEn rise.
> +
> + - devbus,wr-high-ps:   Defines the time during which DEV_WEn is kept
> +                        inactive (high) between data beats of a burst write.
> +                        DEV_A[2:0] and Data are kept valid (do not toggle) for
> +                        <wr-high-ps> - <tick> ps.
> +			This parameter defines the hold time of address and
> +			data after DEV_WEn rise.
> +
> + - devbus,sync-enable: Synchronous device enable.
> +                       1: True
> +                       0: False
> +
> +An example for an Armada XP GP board, with a 16 MiB NOR device as child
> +is showed below. Note that the Device Bus driver is in charge of allocating
> +the mbus address decoding window for each of its child devices.
> +The window is created using the chip select specified in the child
> +device node together with the base address and size specified in the ranges
> +property. For instance, in the example below the allocated decoding window
> +will start at base address 0xf0000000, with a size 0x1000000 (16 MiB)
> +for chip select 0 (a.k.a DEV_BOOTCS).
> +
> +This address window handling is done in this mvebu-devbus only as a temporary
> +solution. It will be removed when the support for mbus device tree binding is
> +added.
> +
> +The reg property implicitly specifies the chip select as this:
> +
> +  0x10400: DEV_BOOTCS
> +  0x10408: DEV_CS0
> +  0x10410: DEV_CS1
> +  0x10418: DEV_CS2
> +  0x10420: DEV_CS3
> +
> +Example:
> +
> +	devbus-bootcs at d0010400 {
> +		status = "okay";
> +		ranges = <0 0xf0000000 0x1000000>; /* @addr 0xf0000000, size 0x1000000 */
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +
> +		/* Device Bus parameters are required */
> +
> +		/* Read parameters */
> +		devbus,bus-width    = <8>;
> +		devbus,turn-off-ps  = <60000>;
> +		devbus,badr-skew-ps = <0>;
> +		devbus,acc-first-ps = <124000>;
> +		devbus,acc-next-ps  = <248000>;
> +		devbus,rd-setup-ps  = <0>;
> +		devbus,rd-hold-ps   = <0>;
> +
> +		/* Write parameters */
> +		devbus,sync-enable = <0>;
> +		devbus,wr-high-ps  = <60000>;
> +		devbus,wr-low-ps   = <60000>;
> +		devbus,ale-wr-ps   = <60000>;
> +
> +		flash at 0 {
> +			compatible = "cfi-flash";
> +
> +			/* 16 MiB */
> +			reg = <0 0x1000000>;
> +			bank-width = <2>;
> +			#address-cells = <1>;
> +			#size-cells = <1>;
> +
> +			/*
> +			 * We split the 16 MiB in two partitions,
> +			 * just as an example.
> +			 */
> +			partition at 0 {
> +				label = "First";
> +				reg = <0 0x800000>;
> +			};
> +
> +			partition at 800000 {
> +				label = "Second";
> +				reg = <0x800000 0x800000>;
> +			};
> +		};
> +	};
> diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
> index 067f311..29a11db 100644
> --- a/drivers/memory/Kconfig
> +++ b/drivers/memory/Kconfig
> @@ -20,6 +20,16 @@ config TI_EMIF
>  	  parameters and other settings during frequency, voltage and
>  	  temperature changes
>  
> +config MVEBU_DEVBUS
> +	bool "Marvell EBU Device Bus Controller"
> +	default y
> +	depends on PLAT_ORION && OF
> +	help
> +	  This driver is for the Device Bus controller available in some
> +	  Marvell EBU SoCs such as Discovery (mv78xx0), Orion (88f5xxx) and
> +	  Armada 370 and Armada XP. This controller allows to handle flash
> +	  devices such as NOR, NAND, SRAM, and FPGA.
> +
>  config TEGRA20_MC
>  	bool "Tegra20 Memory Controller(MC) driver"
>  	default y
> diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
> index 9cce5d7..969d923 100644
> --- a/drivers/memory/Makefile
> +++ b/drivers/memory/Makefile
> @@ -6,5 +6,6 @@ ifeq ($(CONFIG_DDR),y)
>  obj-$(CONFIG_OF)		+= of_memory.o
>  endif
>  obj-$(CONFIG_TI_EMIF)		+= emif.o
> +obj-$(CONFIG_MVEBU_DEVBUS)	+= mvebu-devbus.o
>  obj-$(CONFIG_TEGRA20_MC)	+= tegra20-mc.o
>  obj-$(CONFIG_TEGRA30_MC)	+= tegra30-mc.o
> diff --git a/drivers/memory/mvebu-devbus.c b/drivers/memory/mvebu-devbus.c
> new file mode 100644
> index 0000000..978e8e3
> --- /dev/null
> +++ b/drivers/memory/mvebu-devbus.c
> @@ -0,0 +1,340 @@
> +/*
> + * Marvell EBU SoC Device Bus Controller
> + * (memory controller for NOR/NAND/SRAM/FPGA devices)
> + *
> + * Copyright (C) 2013 Marvell
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + *
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/clk.h>
> +#include <linux/mbus.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +
> +/* Register definitions */
> +#define DEV_WIDTH_BIT		30
> +#define BADR_SKEW_BIT		28
> +#define RD_HOLD_BIT		23
> +#define ACC_NEXT_BIT		17
> +#define RD_SETUP_BIT		12
> +#define ACC_FIRST_BIT		6
> +
> +#define SYNC_ENABLE_BIT		24
> +#define WR_HIGH_BIT		16
> +#define WR_LOW_BIT		8
> +
> +#define READ_PARAM_OFFSET	0x0
> +#define WRITE_PARAM_OFFSET	0x4
> +
> +static const char * const devbus_wins[] = {
> +	"devbus-boot",
> +	"devbus-cs0",
> +	"devbus-cs1",
> +	"devbus-cs2",
> +	"devbus-cs3",
> +};
> +
> +struct devbus_read_params {
> +	u32 bus_width;
> +	u32 badr_skew;
> +	u32 turn_off;
> +	u32 acc_first;
> +	u32 acc_next;
> +	u32 rd_setup;
> +	u32 rd_hold;
> +};
> +
> +struct devbus_write_params {
> +	u32 sync_enable;
> +	u32 wr_high;
> +	u32 wr_low;
> +	u32 ale_wr;
> +};
> +
> +struct devbus {
> +	struct device *dev;
> +	void __iomem *base;
> +	unsigned long tick_ps;
> +};
> +
> +static int get_timing_param_ps(struct devbus *devbus,
> +			       struct device_node *node,
> +			       const char *name,
> +			       u32 *ticks)
> +{
> +	u32 time_ps;
> +	int err;
> +
> +	err = of_property_read_u32(node, name, &time_ps);
> +	if (err < 0) {
> +		dev_err(devbus->dev, "%s has no '%s' property\n",
> +			name, node->full_name);
> +		return err;
> +	}
> +
> +	*ticks = (time_ps + devbus->tick_ps - 1) / devbus->tick_ps;
> +
> +	dev_dbg(devbus->dev, "%s: %u ps -> 0x%x\n",
> +		name, time_ps, *ticks);
> +	return 0;
> +}
> +
> +static int devbus_set_timing_params(struct devbus *devbus,
> +				    struct device_node *node)
> +{
> +	struct devbus_read_params r;
> +	struct devbus_write_params w;
> +	u32 value;
> +	int err;
> +
> +	dev_dbg(devbus->dev, "Setting timing parameter, tick is %lu ps\n",
> +		devbus->tick_ps);
> +
> +	/* Get read timings */
> +	err = of_property_read_u32(node, "devbus,bus-width", &r.bus_width);
> +	if (err < 0) {
> +		dev_err(devbus->dev,
> +			"%s has no 'devbus,bus-width' property\n",
> +			node->full_name);
> +		return err;
> +	}
> +	/* Convert bit width to byte width */
> +	r.bus_width /= 8;
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,badr-skew-ps",
> +				 &r.badr_skew);
> +	if (err < 0)
> +		return err;
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,turn-off-ps",
> +				 &r.turn_off);
> +	if (err < 0)
> +		return err;
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,acc-first-ps",
> +				 &r.acc_first);
> +	if (err < 0)
> +		return err;
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,acc-next-ps",
> +				 &r.acc_next);
> +	if (err < 0)
> +		return err;
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,rd-setup-ps",
> +				 &r.rd_setup);
> +	if (err < 0)
> +		return err;
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,rd-hold-ps",
> +				 &r.rd_hold);
> +	if (err < 0)
> +		return err;
> +
> +	/* Get write timings */
> +	err = of_property_read_u32(node, "devbus,sync-enable",
> +				  &w.sync_enable);
> +	if (err < 0) {
> +		dev_err(devbus->dev,
> +			"%s has no 'devbus,sync-enable' property\n",
> +			node->full_name);
> +		return err;
> +	}
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,ale-wr-ps",
> +				 &w.ale_wr);
> +	if (err < 0)
> +		return err;
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,wr-low-ps",
> +				 &w.wr_low);
> +	if (err < 0)
> +		return err;
> +
> +	err = get_timing_param_ps(devbus, node, "devbus,wr-high-ps",
> +				 &w.wr_high);
> +	if (err < 0)
> +		return err;
> +
> +	/* Set read timings */
> +	value = r.bus_width << DEV_WIDTH_BIT |
> +		r.badr_skew << BADR_SKEW_BIT |
> +		r.rd_hold   << RD_HOLD_BIT   |
> +		r.acc_next  << ACC_NEXT_BIT  |
> +		r.rd_setup  << RD_SETUP_BIT  |
> +		r.acc_first << ACC_FIRST_BIT |
> +		r.turn_off;
> +
> +	dev_dbg(devbus->dev, "read parameters register 0x%p = 0x%x\n",
> +		devbus->base + READ_PARAM_OFFSET,
> +		value);
> +
> +	writel(value, devbus->base + READ_PARAM_OFFSET);
> +
> +	/* Set write timings */
> +	value = w.sync_enable  << SYNC_ENABLE_BIT |
> +		w.wr_low       << WR_LOW_BIT      |
> +		w.wr_high      << WR_HIGH_BIT     |
> +		w.ale_wr;
> +
> +	dev_dbg(devbus->dev, "write parameters register: 0x%p = 0x%x\n",
> +		devbus->base + WRITE_PARAM_OFFSET,
> +		value);
> +
> +	writel(value, devbus->base + WRITE_PARAM_OFFSET);
> +
> +	return 0;
> +}
> +
> +static int mvebu_devbus_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = pdev->dev.of_node;
> +	struct device_node *parent;
> +	struct devbus *devbus;
> +	struct resource *res;
> +	struct clk *clk;
> +	unsigned long rate;
> +	const __be32 *ranges;
> +	int err, cs;
> +	int addr_cells, p_addr_cells, size_cells;
> +	int ranges_len, tuple_len;
> +	u32 base, size;
> +
> +	devbus = devm_kzalloc(&pdev->dev, sizeof(struct devbus), GFP_KERNEL);
> +	if (!devbus)
> +		return -ENOMEM;
> +
> +	devbus->dev = dev;
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	devbus->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(devbus->base))
> +		return PTR_ERR(devbus->base);
> +
> +	clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +	clk_prepare_enable(clk);
> +
> +	/*
> +	 * Obtain clock period in picoseconds,
> +	 * we need this in order to convert timing
> +	 * parameters from cycles to picoseconds.
> +	 */
> +	rate = clk_get_rate(clk) / 1000;
> +	devbus->tick_ps = 1000000000 / rate;
> +
> +	/* Read the device tree node and set the new timing parameters */
> +	err = devbus_set_timing_params(devbus, node);
> +	if (err < 0)
> +		return err;
> +
> +	/*
> +	 * Allocate an address window for this device.
> +	 * If the device probing fails, then we won't be able to
> +	 * remove the allocated address decoding window.
> +	 *
> +	 * FIXME: This is only a temporary hack! We need to do this here
> +	 * because we still don't have device tree bindings for mbus.
> +	 * Once that support is added, we will declare these address windows
> +	 * statically in the device tree, and remove the window configuration
> +	 * from here.
> +	 */
> +
> +	/*
> +	 * Get the CS to choose the window string.
> +	 * This is a bit hacky, but it will be removed once the
> +	 * address windows are declared in the device tree.
> +	 */
> +	cs = (((unsigned long)devbus->base) % 0x400) / 8;
> +
> +	/*
> +	 * Parse 'ranges' property to obtain a (base,size) window tuple.
> +	 * This will be removed once the address windows
> +	 * are declared in the device tree.
> +	 */
> +	parent = of_get_parent(node);
> +	if (!parent)
> +		return -EINVAL;
> +
> +	p_addr_cells = of_n_addr_cells(parent);
> +	of_node_put(parent);
> +
> +	addr_cells = of_n_addr_cells(node);
> +	size_cells = of_n_size_cells(node);
> +	tuple_len = (p_addr_cells + addr_cells + size_cells) * sizeof(__be32);
> +
> +	ranges = of_get_property(node, "ranges", &ranges_len);
> +	if (ranges == NULL || ranges_len != tuple_len)
> +		return -EINVAL;
> +
> +	base = of_translate_address(node, ranges + addr_cells);
> +	if (base == OF_BAD_ADDR)
> +		return -EINVAL;
> +	size = of_read_number(ranges + addr_cells + p_addr_cells, size_cells);
> +
> +	/*
> +	 * Create an mbus address windows.
> +	 * FIXME: Remove this, together with the above code, once the
> +	 * address windows are declared in the device tree.
> +	 */
> +	err = mvebu_mbus_add_window(devbus_wins[cs], base, size);
> +	if (err < 0)
> +		return err;
> +
> +	/*
> +	 * We need to create a child device explicitly from here to
> +	 * guarantee that the child will be probed after the timing
> +	 * parameters for the bus are written.
> +	 */
> +	err = of_platform_populate(node, NULL, NULL, dev);
> +	if (err < 0) {
> +		mvebu_mbus_del_window(base, size);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id mvebu_devbus_of_match[] = {
> +	{ .compatible = "marvell,mvebu-devbus" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, mvebu_devbus_of_match);
> +
> +static struct platform_driver mvebu_devbus_driver = {
> +	.probe		= mvebu_devbus_probe,
> +	.driver		= {
> +		.name	= "mvebu-devbus",
> +		.owner	= THIS_MODULE,
> +		.of_match_table = mvebu_devbus_of_match,
> +	},
> +};
> +
> +static int __init mvebu_devbus_init(void)
> +{
> +	return platform_driver_register(&mvebu_devbus_driver);
> +}
> +module_init(mvebu_devbus_init);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>");
> +MODULE_DESCRIPTION("Marvell EBU SoC Device Bus controller");
> -- 
> 1.8.1.5
>